Saw forming device



June 23, 19.31. c. c. KNAPP 1,811,236

' SAW 1 011141110 DEVICE Filed April 11. 1928 2 Sheets- Sheet 1 5: 4 -1.93 l/ @511 i/ 2/ 421/ Z; 20-

K n INVENTOR 4 6073 36 c2 BY Q. K

ATTORNEYS June 23, 1931. c; c. KNAPP' S AW FORMING DEVICE Filed April11, 1928 2 Sheets-Sheet 2 a 1NVENTOR I ad/Mud, AI TORN EYS and somounted that the Patented June 23, 1931 UNITED STA TES PATENT OFFICECHARLES C. KNAPP, OF JERSEY CITY, NEW JERSEY, ASSIGNOR 'OF ONE-HALF TOBOSWELL B. SMITH, OF BROOKLYN, NEW YORK SAW FORMING DEVICE Applicationfiled April 11,

This invention relates to the manufacture of saws and has for its objectthe provision of an improved apparatus and method for manufacturingsaws. More particularly, the invention relates to the provision of animproved apparatus for forming jewelers saws and band saws such as areused, for instance, in scroll cutting.

According to some present practices, saws of the above types are formedby punching the teeth by hand or subjectin a. strip of saw stock to theaction of grin ers, cutters, or punches which rotate about axes whichare substantially parallel with the side edges of the strip. Accordingto other present practices, mechanically operated reciprocat ing diesprovided with sufficient teeth to forma complete saw blade are used. Ithas also been proposed to use apparatus provided with rotary dies havingperipheral punches eripheral punches of one mesh with those of theother.

The methods and apparatus heretofore commonly used have been found to beunsatisfactory for many reasons. In many instances, the apparatusemployed is incapable of producing saws having uniform and accurateteeth. In the instances where accurate saws are produced, the capacityof the apparatus is low with the result that the cost of the saws isrelatively high. The manufacture 7 of each saw blade or pair of bladesaccording to the present practices, is a relatively slow and tediousprocess involving several separate and distinct operations, and110-211)- para-tus or method by means of which finished saw blades maybe formed continuously and accurately'from a continuous band of sawstock has been employed heretofore. Furthermore, in the manufacture ofsaw blades with the present machines and according to the presentmethods, it is necessary that soft metal saw stock be used, whichnecessitates subjecting the blades to a hardening process as a result ofwhich the blades become highly brittle and easily breakable.

The present invention contemplates the provision of an improvedapparatus by means of which individual saw blades may becontinuously andaccurately formed from a con- 1928. Serial in. 269,141.

tinuous strip or band of tempered steel. The invention furthercontemplates the provision of a machine which embodies tooth-formingmeans, tooth-setting means, and severing means to the end thatcompletely finished saws may be produced by means of a single operation.

Machines embodying the. present invention are provided with twosuperposed circular dies which rotate about spaced parallel axes. Thedies are provided on their adjacent end faces with groups ofcomplementary teeth and peripheral cutting edges which cooperate toshear or slit a strip of saw stock longitudinally, 'and provide twoseparate strips hav mg spaced groups of teeth. Means are also providedfor setting the teeth of the two str ps simultaneously and for severingthe strips transversely intermediate the groups of teeth. Improvedfeeding and guiding means are provided for delivering the saw stock tothe tooth-forming dies and for delivering the two strips formed by thedies in proper relative positions to the tooth-setting and severingmeans.

Machines embodying the invention ma be provided with dies having teethforme on their entire adjacent end faces for producing continuous bandsaws, in which event the severing means and tooth-setting means may beeliminated.

The novel features of the invention will be best understood fromthefollowing description taken in conjunction with the accompanylngdrawings, in which Fig. 1 is a sectional elevation taken substant-iallyon the line 11 of Fig. 4 and showpositions of the cutting dies,

ing the relative feed rollers and severing means;

Fig. 2 is a side elevation of the apparatus showing a portion of thedriving means;

.Fig. 3 is a side elevation showing means for driving the. upper die;

Fig. 4 is a sectional elevation taken sub stantially on the line 4-'4ofFig. l and show- Fig. 6 is a sectional elevation taken stantiall onthe line 66 of Fig. 1 and showing the eed rollers and the adjustableguid'"' ing means mounted thereon; I

Fig. 7 is an enlarged fragmentary sectional view of the dies showing theteeth and the peripheral cutting edges for "forming the teeth andslitting'the strip of saw stock longitudinally; and showing a strip ofsaw stock being subjected to the cutting action of the' Fig. 8 shows afragment of saw stock in which the teeth have been formed midway betweenthe side edges;

Fig. 9 shows'a fragment of saw stock in which the teeth have been formedadjacent one side edge;

Fig. 10 shows a completed jewelers saw formed by the apparatus of theinvention;

Fig. 11 is a fragmentary view of the severing rollers provided withtooth-setting means; and

Fig. 12 is a transverse section throu h a jeweler's saw the teeth ofwhich have can set.

Similar reference characters refer to similar parts throughout theseveral views of the drawings.

The embodiment shown in the drawings .comprises a frame formed of'twospaced,

substantially vertically extending metal plates 20 rigidly connected bymeans of upper and lower transverse braces 21 and 22.

Upper and lower circular dies 23 and 24 are rigidly mounted upon upperand lower die shafts 25 and 26. Locking collars 27 provided with setscrews 30 are mounted upon the shafts 25 and 26 and serve to aid inholding the dies in position on their shafts.

The die shafts 25 and 26 extend transversely between the metal plates20, and their end portions are journaled in upper and lower rectangularbearing blocks 31 and 32 which are adj ustably mounteiwithin rectangularopen ended'slots 33 in the plates 20. The blocks 31 and 32 are providedwith grcoves which are'adapted to receive the portions of the walls 20which are immediately adjacent the sides thereof. A member 28 isremovably mounted on the top of each plate 20, serving as a closuremember for the open ended slots 33 and permitting removal of the dieshafts and bearing blocks. Each die shaft isprovided with inner andouter thrust collars 34 which-engage the inner and outer surfaces of theblocks 31 and 32 and lock the shaft against transverse movement;

The upper and lower bearing blocks 31 and 32 at either side of theapparatus are spaced apart by means of double ended screws 35 havingright and left hand threaded end portions which enter threaded recessesin the adjacent end surfaces of the blocks, and they are held in spacedrelation to the end walls of the slots 33 by means of screws 36 whichextend through vertically extending threaded openings m the portions ofthe plates 20 walls of the slots 33. The die shafts may be movedrelatively to'each other and to the upper and lower ends of the slots33, and the dies 23 and 24 may be adjusted relatively to each otherthrough manipulation of the screws 35 and 36.

An end face of each of the dies 23 and 24 is provided with two groups ofradial projections or teeth 37 and intermediate grooves. The peripheralsurfaces of the projections are flush with the adjacent peripheralsurface of the main body portion of the die and correspond in outlineand. area to a tooth of the saw to be formed. The end surfaces 40intermediate the groups of projections are plane and extendsubstantially at right angles to the axes of the die shafts 25 and 26.The surfaces 40 lie in planes which are inter mediate parallel planes inwhich the inner and outer peripheral edges of the teeth 3'? lie, and thesum of the distances of the surfaces 40 from either of said parallelplanes is substantially equal -to the tooth depth.

' The axes of the die shafts 25 and 26 are spaced apart a distancesubstantially equal to the sum of the radii of the dies 23 and 24. Theteeth are so formed that those of one die are complementary to those ofthe other die, and the dies are somounted relatively to each other thatall of the peripheral edge portions of the toothed end of one diecooperate with those ofthe toothed end of the other die to form shearingmeans for any rigid body which may be passed between the dies duringtheir rotation.

Strip supporting rings 41 are mounted on the die shafts in contact withthe toothed members 28 which constitute the end an amount equal to thethickness of the saw stock to be used. Guide rings 42 are mounted on theperipheral surfaces of the main body portions of the dies in threadedengagement therewith, and they may be adjusted to accommodate differentwidths of saw stock.

Upper and lower feed rollers 43 and 44 (Figs. 1 and 6) are rigidlymounted upon parallel shafts 45 and 46 which extend between the plates20 adjacent an end of the supporting frame. The feed roller shafts 45and 46 extend parallel with the die shafts 25 and 26 and than endportions are mounted in bearing blocks 47 and '50 similar to the bearingblocks 31 and 32 in which the end portions of the-die shafts as mounted.

The opposite end portions of the upperfeed roller- 43 are threaded, andthe central portion has a smooth surface and is of slightly greaterdiameter than the end portions (Fig.

projecting, threaded, annular shoulder are adjustably mounted upon thethreaded end portions of the roller 43. Portions of the guide rings 51project over the central portion of the roller 43 and form a channel forthe strip of saw stock.

The lower feed roller 44 has reduced end lgortions and an enlargedcentral portion 52 aving a smooth surface and of a Width preferablyequal to the width of the narrowest strip of saw stock which it will bedesirable to use in making saws. The peripheral edge portion of thecentral portion 52 is normally positioned between the guide rings 51.The surfaces of the central portions of the upper and lower guiderollers 43 and 44 are normally spaced apart a distance equal to thethickness of the strip of saw stock.

The apparatus is provided with a severing and tooth-setting mechanismcomprising upper and lower rollers 53 and 54 (Figs. 1 and 11) which arerigidly mounted upon shafts 55 and 56.- The shafts 55 and 56 extendparallel to the die shafts 25 and 26, and their end portions are mountedin bearing blocks 57 and 60 which are similar to bearings blocks 31 and32 in which the end portions of the die shafts are mounted. The upperroller 53 is similar to the upper feed roller 43 in that it is providedwith threaded end portions and has guide rings 58 similar to the guiderings 51 mounted thereon. The lower 1 roller 54 has an enlarged centralportion the peripheral edge portion of which is positioned between theguide rings 58 carried by the upper roller.

The roller 53 is providedwith recesses 61 in which are mounted knifeblades 62, the cutting edges of which arespaced 180 apart. The roller 54is provided with grooves or' recesses in which are mounted members 63having grooves for the reception of the cutting edges of the knifeblades 62. The portions of the surfaces of the rollers 53 and 54 intermediate the knife blades 62 and the members 63 are provided withdepressions and projections 64 and 65 (Fig. 11) which correspond inoutline and area withthe teeth formed by the dies. The central portionsof the surfaces of the rollers 53 and 54 are normally spaced apart adistance equal to the thickness of the saw stock.

The driving means for the dies, feed rollers and the rollers comprisingthe severing and tooth-setting mechanism comprises a plurality of gearsand a chain all of which are driven by means of a pulley 66 rigidlymounted on the lower die shaft 26 adjacent an end thereof and connectedto a suitable source of power (not-shown).

The rotation of the lower die shaft is transmitted to the upper dieshaft b means of a spiral gear 67 ,rigidly mounte on the end of lowerdie shaft opposite to that on which the pulley 66 is mounted. The spiralgear 67 operates through the spiral gears 70 and 71 to rotate a spiralgear 72 which is rigidly mounted upon an end portion ofthe upper dieshaft. 6

The spiral gears 70 and 71 are mounted on short shafts 73 and 74 carriedby an adjustable supporting frame comprising side members 75 and 76having vertically slotted lower end portions adapted to receive a rod 77which is rigidly mounted upon and projects laterally from a plate 20.The supporting frame is vertically adjustable and it may be lockedagainst vertical movement by means of a nut 80. A link 81 whichispivotally mounted on the shafts 25 and 74 maintains the axes of thesetwo shafts a fixed distance apart. Similarly, a link 82 maintains theshafts 26 and 73 a fixed distance apart.

' The ends of the upper die shaft 25, the

severing mechanism shafts 55 and 56, and the feed roller shafts 45 and46 adjacent the end of the lower die shaft on which the drive pulley 66is mounted are provided with sprockets 83. A-fiexible silent'chain 88 isappropriately mounted upon the sprockets 83 and idler sprockets 84 whichare carried by stub shafts 85 appropriately mounted upon a frame plate20.

Channel members 86 and 87 (Figs. 1 and 5) provide additional means forguiding a strip of saw stock through the machine. The

channel members 86 and 87 are rigidly mounted on vertical supportingmembers 90 and 91 which are mounted for horizontal adjustment on thetransverse braces 21 and- 22'. Locking screws 92 and 93 extend throughvertical threaded openings in the upper end portions of the supportingmembers 90 and 91 and their lower ends are adapted to engage fiatsurfaces 94 on the braces 21. The channel members are provided withplates 95 swiveled on screws 96 which extend through threaded openingsin the side walls of the channels for varying the widths of thechannels. A block or cover member 97 is position'edwithin the channelbetween the plate 95 and the opposite side wall of the channel andserves as a means for confining the strip of saw stock to the bottomportion of the channel.

- In the embodiment shown in the drawings,

the rollers are all of the same diameter and the driving mechanism is soarranged that? they all rotate at the same rate of speed. The

' the toothed ends of the dies.

.is slit longitudinally along alternate straight of the desired type,dies having groups of teeth of the desired number and contour are somounted that the groups of teeth and intermediate peripheral cutting orshearing edges are disposed in the proper relative positions. The feedrollers are spaced apart a distance substantially equal to the thicknessof the strip. Severing and tooth-setting rollers having knife blades ofthe proper width, and having groups of depressions and projectionscorres onding in number and outline to the teet to be produced and ofthe type to givathe desired set are mounted in their proper positionsrelatively to the dies, and. spaced apart a distance substantially equalto the thickness of the strip of saw stock. The guide rings carried bythe rollers and diesare adjusted relatively to the teeth of the dies.The plate and cover members 95 and 97 are adjusted to provide guidechannels of the proper width and thickness and the supporting members 90and 91'are adjusted to aline the channels with the inner surfaces of theguide rings.

A strip of saw stock in passing through the machine passes between thefeed rollers 43 and 44 in engagement therewith, enters the channelmember 87 and passes between the dies 23 and 24. In passing between thedies, the strip is cut in two along a line corresponding. to the outlineof the peripheral edges of Thus the strip and zig-z'ag lines; the zi-zag lines corresponding to the contour of of a saw blade. Thesupporting rings '41 carried by the dies hold the two strips against themain body portions of the dies and thus prevent twisting or distortion.The sup-.

porting rings 41 and guide rings 42 cooperate to prevent separation ofthe two strips.

The two strips in leaving the. dues pass through the channel member. 86which holds to provide .twofstrips each having spaced them in properalinement and passes them 'thus between the rollers comprising thetoothsetting and severing mechanism. The depressions and pro'ectionsare'so arranged that alternate teet are set oppositely and the knifeblades 62 and members 63 are so arranged relatively to the groups ofprojections and depressions that the strips are severed at the desiredpoints between the groups of teeth. 1

Of course, it will be understood that dies having teeth formed on theirentire adjacent end faces or any suitable number of groups of teeth maybe used or not depending upon "I (ilaim y 1.' A saw forming devicecomprisingmeans for slittinga strip of saw stock longitudinally the tvpeof saw which it is desired to produce.

groups "of saw teeth, means for setting said teeth, rmeans for'guidinsaid strips to said tooth-setting means an' for holding. said thetoothed edge strips in engagement witheach other, and

forming saw teeth, means for feeding a strip of saw stock to saiddi'es,-a pair of complementary circular dies for setting teeth formed bysaid tooth-forming dies, and means carried by said setting dies forcutting said strip transversely.

3. Saw forming apparatus comprising a pair of complementary circulardies for forming saw teeth, feed rollers for delivering a strip of sawstock to said dies, a pair of complementary circular dies for settingteeth formed by said tooth-forming dies, and

pair of complementary circular dies for means carried by said settingdies for cutting said strip transversely.

4. Saw forming apparatus comprising a pair of complementary circulardies for forming spacedfgroups of teeth in a strip of saw stock, meansfor feeding a strip of saw stock to said dies, a pair of complementarycircular dies for setting teeth formed by said tooth-forming dies, andmeans carried by said setting dies for cutting said strip transverselybetween the groups of teeth formed by said dies.

5. Saw forming apparatus comprising a pair of complementary circulardies. for forming spaced groups of teeth in a strip of saw stock, feedrollers for delivering a strip of saw stock to said dies, a pair ofcomplementary circular dies for settingteeth formed b said tooth-forming'dies, and means carried by said setting dies for cutting said stritransversely intermediate the groups of teet formed by said dies.

6. Saw forming apparatus comprisin a pair of complementary circular diesfor s itting a strip of saw stock longitudinally to form two separatestrips each having spaced groups of teeth formed therein, means forfeeding a strip of saw stock tosaid dies, 9. pair of complementarycircular dies for setting teeth formed by said tooth-forming 'dies, andmeans carried by said setting dies for cutting said strips transverselybetween the spaced grou s of teeth.

7. A saw orming device comprising means for slitting a strip of sawstock longitudinally to provide two strips each having saw teeth,

means for setting said teeth, and means for guiding said strips from theslitting means to the tooth-setting means, said guiding 420 meanspreventing lateral separation'of the two strips and maintaining themwith their serrated edges in interfitting engagement during theirpassage from the slitting means

